Miniaturized waste heat engine

ABSTRACT

Various embodiments of a converter for use in a combustion engine having a discharge conduit for discharging exhaust combustion gases are disclosed. In one exemplary embodiment, the converter may include a heating chamber being in thermal contact with the discharge conduit and defining a hydraulic channel through which a fluid passes. The converter may also include an inlet port disposed in the heating chamber for receiving the fluid into the heating chamber, and an outlet port disposed in the heating chamber for discharging the fluid from the heating chamber. The heat energy from the exhaust combustion gases is transferred to the fluid while the fluid passes through the hydraulic channel.

This is a continuation of application Ser. No. 12/230,004, filed Aug.21, 2008, which is a continuation of application Ser. No. 10/806,480,filed Mar. 23, 2004, now U.S. Pat. No. 7,430,865, which is acontinuation of application Ser. No. 10/066,574, filed Feb. 6, 2002, nowU.S. Pat. No. 6,729,137, which is a continuation of application Ser. No.09/582,233, filed Sep. 7, 2000, now U.S. Pat. No. 6,374,613. All ofthese prior applications are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention is characterized by a combination ofvapor-to-mechanical energy converters driven by rapid heat transfermeans able to instantaneously transfer energy from the products ofcombustion, or any heat source, to a thermodynamic fluid circulatinginside an independent loop. This fluid moves inside the loop mainly as aresult of its own expansion and transfers its energy to mechanical meansthrough thermodynamic work-producing units or expanders. In this manner,the various components of this device constitute a special MiniaturizedWaste Heat Engine (MWHE) able to recuperate and convert waste energyfrom combustion or heat sources into useful energy. By returning asignificant fraction of this recuperated energy to the power system (forexample in the form of mechanical or electrical energy), the usuallyunavoidable heat discharge into the environment is minimized, whilepollutant emission can be significantly reduced at no energy cost forthe power system.

To simplify the description of the working principles and methods ofoperation of this invention, an internal combustion engine (fueled withheavy or non-heavy fuels) is from now on considered to be the powersystem. However, any power system utilizing heat sources and producingwaste heat as a result of their operation could utilize the techniquesand methods described by this invention.

When this invention is applied to an internal combustion engine, theenergy of the exhaust combustion gases (high temperature and mass flowrate) is converted into additional horsepower transferred directly tothe engine load, via the engine crankshaft, and/or indirectly viaspecial engine intake oxygen enhancing means.

The MWHE contains one or more vapor-to-mechanical energy convertingsystems, referred to hereafter as expanders; one or more instantaneousheat transfer systems, referred to hereafter as converters; one or moreinstantaneous vapor collapsing systems, referred to hereafter asimploders; and one or more air/oxygen enhancing systems, referred tohereafter as oxygenators.

In general, the MWHE is formed by one or more converters coupled with aseries of expanders including a vapor condensing system, or imploder, soas to form a thermodynamic cycle. A converter (or multiple converters)returns the recuperated energy from the exhaust gases through one ormore expanders in the form of mechanical energy, adding it to the powernormally generated by the engine. Another converter (or the excessrecuperated energy of a single converter) allows the pressurization ofthe engine intake manifold through the oxygenator, thereby providingexcess oxygen to the air fuel mixture independently of the enginerotational speed, or revolutions per minute (RpM). By utilizing thisparticular oxygen enhancing feature, the engine performance can besignificantly improved since air/oxygen is virtually pumped into theengine at all times, regardless of the RpM, at no cost. If this deviceis applied to a diesel fuel engine, the production of highly toxicparticulate is almost eliminated since excess oxygen is always presentduring combustion, even when the engine is accelerating from idlingspeeds.

Therefore, the main application of this thermodynamic engine can be seenas an anti-pollution system, especially when applied to heavy fueledengines, but also as a device able to significantly improve engineperformance while reducing fuel consumption. Again, it is important toemphasize that the source of energy of this invention is constituted byheat that is normally irreversibly discharged into the environment.

PRIOR ART

Engine intake air-enhancement-systems are normally characterized bycentrifugal turbo-compressors, or turbo-chargers, and by positivedisplacement air compressors. The centrifugal compressors are devicesutilized to provide excess air to the engine allowing increased poweroutput and generally improving the combustion. These devices improve theoverall engine efficiency because they recuperate a fraction of thekinetic energy and pressure energy contained in the exhaust gasesproduced during combustion. Centrifugal compressors are widely used inInternal Combustion (IC) engine applications since they show reasonablygood efficiencies when they operate at the proper speeds, are reasonablyrugged, and last for the entire life of the engine. Air compressors forIC engines are generally formed by two counter-opposed sectionscontaining the Exhaust Gas Wheel, “EGW,” and the Compressor Wheel, “CW,”connected by a common shaft. The EGW converts parts of the kinetic andpressure energy of the exhaust gas into shaft power. Since the CW isalso mechanically connected to the same shaft, it converts the shaftpower provided by the EGW into air pressure at the discharge of the CW.In this manner, the engine intake manifolds become pressurized and moreair/oxygen is available to the engine. Thanks to these devices, it ispossible to increase the amount of fuel injected in the combustionchamber and increase the overall engine power output. Unfortunately, theefficiency of the centrifugal compressors is optimized only for asignificantly high range of rotational speed of the CW (generallygreater than 30,000 RpM). Such speeds are only reached when the mass ofexhaust gases (mass flow rate, grams-per-second), matches the optimizedEGW RpM, so that the maximum torque is transferred through the shaft tothe CW. This unavoidable sequence of events creates the conditions for adelay, called “turbo-lag,” imposed mainly by the fluid-mechanicalinertia of the exhaust gases, the mechanical inertia of the EGW, CW, andmany other factors. Due to the fact that the exhaust gases are aconsequence of the combustion process, the engine experiences asignificant delay between the time the fuel is injected and the time theproper quantity of oxygen in the combustion chamber is made available bythe compressor. This delay provokes a severe drop in engine performanceduring acceleration, particularly from idling to higher RpM. In fact,during these phases there is not enough oxygen to complete combustion,therefore the production of pollutant emissions is significant while theengine performance is impaired. This condition exists for severalseconds every time the engine accelerates and it becomes even morepronounced when the engine is severely loaded.

Normally, if the engine is idling and the accelerator pedal is suddenlypressed, the fuel appears inside the combustion chambers almostinstantaneously, but the availability of oxygen is completelyinsufficient to complete combustion. Eventually, the engine RpM changesfrom idling to the desired speed and an increasing mass flow of exhaustgases starts to provide enough torque to the centrifugal compressor,thereby the availability of oxygen becomes gradually sufficient. Infact, as time passes the CW reaches the proper RpM and air is finallycompressed inside the intake manifold. To summarize, during accelerationthe conventional turbo compressors (centrifugal compressors inparticular) are unable to provide oxygen to the engine for a time perioddepending on engine load and rate of acceleration. During this time asevere production of particulate (especially when heavy fuels areconsidered) is discharged into the environment. To eliminate, orminimize, the turbo-lag phenomena, some engine manufacturers utilizedifferent mechanical compressors (i.e. positive displacementcompressors) which show a reasonable efficiency at low RpM. Thesemechanical systems are coupled with the engine crankshaft, therebyutilizing power from the engine to operate (less efficient). When thesedevices are utilized the production of pollution is reduced duringacceleration, but unfortunately engine performance is also penalized,especially at high engine RpM. The only commercial alternative widelyused (for example for large diesel engines) is to utilize two differentair-enhancing systems in tandem. Therefore, a positive displacement aircompressor, utilizing power from the engine, and a centrifugalcompressor are coupled so that one provides oxygen at low RpM, while theother pressurizes the intake manifold at higher RpM. This solution isvery expensive and results only in a modest improvement of the overallengine efficiency. Another way to provide excess oxygen inside theintake manifold at low engine RpM is represented by electricalcompressor. These compressors are generally characterized by anelectrical motor coupled with a centrifugal compressor able to provideexcess oxygen to the engine independently of engine RpM. Generally,these electrical motors are controlled by sophisticated and expensiveelectronic controllers, and require extremely high current densities toprovide the needed torque in a few hundreds of milliseconds. In otherwords, these compressors are capable of providing the needed oxygen atlow engine RpM, but unfortunately they require extremely high electricconsumption for their operation. The high current densities required forthe electrical air compressors also poses serious problems byoriginating large emissions of electromagnetic interference, and bygenerally overloading the conventional electrical systems (i.e.alternator, batteries) aboard the vehicles. Therefore, although theelectric compressors satisfy the requirement for oxygen at low engineRpM, they also require so much power to run that the overall energybalance might actually show a deterioration of the overall engineperformance instead of the opposite.

The main objective of the proposed invention is to provide a wasteenergy recovery system capable of reducing environmental pollution whileincreasing the engine performance. Therefore, this invention convertsheat into mechanical energy which can be used to produce electricity,air pressure, or availability of thermodynamic work.

SUMMARY OF THE INVENTION

One of the main objectives of the proposed invention is to provide ananti-pollution device while increasing the power system's overallperformance without affecting the fuel specific consumption. In general,this invention consists of a special thermodynamic engine coupled withthe power system, the waste energy of which is the source of energy ofthe thermodynamic engine. Because the converters and expanders utilizedare extremely compact, the overall MWHE can be easilyassembled/integrated with a conventional IC engine. Superheated vapor isgenerated by injecting a relatively low-pressure fluid with the desiredthermodynamic and thermal physical properties (i.e. water or any properfluid) inside a special heat transfer converter which transfers the heatreleased by the cooling system and exhaust gases of the engine to thefluid instantaneously. In general, by considering a 50-60 horse-power(HP) engine, about 20-24 kW (where 1 kW=1.341 HP) are normally lost inthe form of heat irreversibly discharged into the environment. This heatis normally lost through the exhaust gases and forced convection throughthe engine coolant system and radiator. The minimum energy required toaccumulate enough oxygen inside the intake manifold when the engine isaccelerating from idling to higher speeds can be estimated between 0.8-1kW for a small volume engine, and about 3 kW for a medium largediesel-fueled engine. Normally the efficiency of a standard centrifugalair compressor is not greater than 60-70%, therefore the energy requiredat the compressor shaft is about 3.2 kW. A device utilizing a 20 kWenergy source to convert it into 3.2 kW minimum energy required toprovide compressed air should have an efficiency of at least 16%. Such alow efficiency is normally not even considered for power generation;however, in this case the energy source is waste energy and recuperatingeven a small fraction of it only represents a gain for the overallengine efficiency. Therefore, the thermodynamic cycle of the NWHE is avapor cycle based on an injection of water (or a proper fluid) into theheat transfer converter which instantaneously flashes the water tosuperheated steam with no need for steam boilers or accumulation (as isfor conventional vapor cycles). The pressure of the water injection andthe mass flow rate can be varied as a result of the quantity of heatavailable inside the converter, or simply as a function of the amount ofwaste heat that we want to recuperate. Once water is injected inside theconverter it expands instantaneously, changing its specific volume andmaking the heat transfer process extremely rapid. The energy collectedby the superheated steam while transiting inside the converter is thenutilized inside one or more expanders able to provide power directly tothe crankshaft, and/or drive the oxygenators. If the engine is amedium-large volume engine the production of waste heat is greater thanthe heat necessary to only drive the oxygenators. In this case, theexcess superheated steam energy can be utilized to drive an additionalexpander that returns (directly or indirectly) mechanical energy to theengine crankshaft. To summarize, the MWHE can be formed by one or moreheat converters, and at least two expanders. One expander is coupledwith the engine load through a special clutch, and the other provides aconstant optimum speed for a special centrifugal-type compressor formingan air/oxygen enhancing system (oxygenator) powered by waste energy. Thesuperheated steam formed inside the converter then expands in theexpanders and condenses inside a radiator, or as a result of steamcollapsing when exposed to the cold surfaces of chambers inside theexpander (imploding systems). Furthermore, the sudden implosion of vaporinside the imploder chambers causes a drop in the system pressure (i.e.P=0.09 bar when T=45° C.) which increases the efficiency of the MWHEthermodynamic cycle. At this point the condensed fluid (back in itsliquid form) is pressurized back into the injector, and a new cyclestarts over. By rough estimates, it is possible to assume that if themaximum temperature reached by the superheated steam inside theconverter is only 450° C., the overall efficiency of the waste heatthermodynamic cycle is approximately 21%. This means that a vapor cyclewith the above characteristics could provide at least 3.4 kW shaft powerto a compressor of whatever type. In other words, the thermodynamicengine described in this invention can be utilized to power anair/oxygen enhancing system at no cost for the overall energy balance ofthe engine. If the converter provides a superheating temperature greaterthan 450° C., for example 600° C., the overall efficiency of thethermodynamic cycle would reach 29%. The maximum temperature achievableby the superheated vapor inside the converter is proportional to: thelength of the converter; the distance between heated surfaces inside theconverter; the roughness of the converter internal surfaces; mass flowrate of liquid fluid to be converted into vapor; mass flow rate ofexhaust gases transiting inside the converter; thermal insulationbetween converter and surrounding environment; and many other lesscrucial variables. In general, exhaust gases temperatures can reachvalues higher than 600° C., and the relative efficiency of the convertercan be much higher than 29%.

To summarize, the device of this invention recuperates a fraction of theenergy normally lost in the form of heat from conventional power systemsand combustion engines. By utilizing this energy to drive oxygenenhancing systems, engine pollution can be drastically reduced whileengine performance is increased. By utilizing this same energy to drivea work-producing unit, the overall engine efficiency can be furtherimproved since more power can be provided to the engine load. Then theoverall engine power output is a result of the summation of the powernormally provided by the engine and the power recuperated from the wasteheat.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representation of a basic centrifugal air compressor withinwhich an additional work-producing unit is added in the central body ofthe compressor, thereby forming an intake air-enhancing system whichutilizes the exhaust gases kinetic energy in tandem with the expansionof superheated vapor inside an expander coaxial with the CW.

FIG. 2 is a sectional view representing the mechanical parts of thework-producing unit which can be assembled inside the body of widelyused centrifugal compressors. This work-producing unit includes activemeans for the optimum regulation of the expander speed along with anautonomous and innovative lubrication system.

FIG. 3 is a sectional view of the central body of the expander whichutilizes an internal imploding chamber/surface able to cause suddenvapor condensation.

FIGS. 3A and 3B are sectional views representing the central body of theexpander equipped with active servo mechanisms controlling andregulating special vapor nozzles.

FIG. 4 is a schematic representing the hydraulic lubricating system andthe pumping effect caused by internal blades embedded into the shaft.

FIG. 4A is a sectional view of the expander in which the outlet nozzlesare oriented in a configuration which offers a counter balancing forcefor the thrust bearings.

FIG. 4B is a sectional view of the expander coupled with a CW in anup-side-down configuration and equipped with a balancing variable masssystem.

FIG. 5 is a sectional view of a special expander whose wheel containsmultiple stage blades within the same circumference, coupled with acentrifugal CW and an EGW showing also an external jacket for thereutilization of the heat loss by the surfaces of the EGW casing.

FIG. 6 is a sectional view of an expander similar to that described inFIG. 5 except that the vapor circulates inside a jacketed systemsurrounding the EGW casing independently of the vapor circulating insidethe expander.

FIG. 7 shows a detailed representation of the multiple stage bladeslocated on a single wheel, lighter, compact, and able to provide thetorque of three equivalent wheels operating with vapor with differentthermodynamic properties.

FIG. 8 is a sectional view of a special expander coupled with acentrifugal CW positioned with 180° rotation and having a dischargesection formed by a diverging conical nozzle able to recuperate most ofthe kinetic energy of the air once leaving the blade tips of the CW. Inthis Figure a series of intake air by-pass valves are also shown.

FIG. 9 is a sectional view of a centrifugal compressor coupled with avapor expander completely symmetric for easiness of manufacturing andassembly.

FIG. 10 is a sectional view of an expander forming a work-producing unitcoupled via reduction gears to a centrifugal, mechanical, hydraulic, orelectromagnetic clutch which transfers mechanical energy to the engineload.

FIG. 11 represents the application of the expander-compressor unit as anoxygen enhancing system connected directly on the air filter barrel ofthe engine intake manifold without affecting the operation of existingturbo compressors or turbochargers already installed on the engine.

FIG. 12 represents the application of the expander-compressor unit as anoxygen enhancing system positioned inside the intake manifold utilizinga jet effect to pressurize the intake manifold. Again, this applicationdoes not affect existing turbo chargers or compressors already installedon the engine.

FIG. 13 shows the optimization of a conventional turbo compressor. Inthis case, the expander-compressor air/oxygen intake is independent andthe pumping jet effect is optimized for higher performance at low engineRpM.

FIG. 14 shows a series of different configurations of the expandercompressor unit by coupling the expander to existing compressor parts,or by coupling the expander to specially manufactured parts (i.e.special multiple stage blades wheel, or symmetric parts).

FIG. 15 shows the hydraulic circuits of the various heat converterslocated inside the muffler, inside or surrounding the exhaust manifold,and the jacket surrounding the EGW casing. In this Figure, the heatconverter formed by a jacket in thermal contact with the hot surfacesexposed to hot exhaust gases driving the wheel, and thermally insulatedfrom the surrounding environment, forms a hydraulic path which allowssuperheated vapor to flow directly into the expander (shown in detail inFIG. 5).

FIG. 15A shows a cooling system formed by heat fins/vents of theconverter positioned onto or inside the exhaust manifoldable tore-circulate cooling air in case of malfunctioning of the converter orthe MWHE.

FIG. 16 shows a hydraulic circuit similar to that shown in FIG. 15. Inthis Figure the connection of the various converters allows furthersuperheating of the vapor and increases the overall efficiency of theMWHE.

FIG. 17 is a schematic representing the thermodynamic cycle made by thefluid (i.e. water or any proper fluid) from the condenser to theconverter(s), to the expander(s), and back to the condenser.

FIG. 17A is a schematic representing the thermodynamic cycle as shown inFIG. 17 with the addition of a high pressure insulated accumulation tankin which excess waste heat can be accumulated to pulse the expanders.

FIG. 18 represents a sectional view of a heat converter of easyconstruction and equipped with internal fins/paths for a better heattransfer, thermally insulted with proper materials or by means of anadditional jacket in which it is possible to obtain a vacuum and goodthermal insulation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The working principles of the MWHE of the present invention are nowdescribed by utilizing the schematics and representations shown in FIG.1-18.

The thermodynamic steps of the MWHE's cycle are represented in FIGS. 17,and 17A. Since the MWHE is formed by the combination of severalsub-components, each of them characterized by unique features, thedescription of the MWHE should be somewhat simplified by describing thesub-components first. The most important sub-components of the MWHEcycle, expanders, converters, imploders, oxygenators and theirapplications are described in FIG. 1-16. FIGS. 17 and 17A, and basicallyprovide the overall hydraulic connection and method of operation of eachsub-component as part of a single device: the MWHE as a plant.Therefore, the basic components of a centrifugal compressor modified tointegrate the vapor expander block of the MWHE are shown in FIG. 1. Thebody of the expander 1 is comprised inside the dashed block of FIG. 1.The vapor expander 1 contains at least one bladed Expander Wheel “EW,”6, with blades 6 a designed to provide the proper torque at a desiredmass flow rate and thermodynamic properties of the vapor. The materialof the wheel itself can be metal, composite, or a combination. Ingeneral, the material of the wheel has to have enough strength tosustain the mechanical stress imparted by the vapor, and it has to havegood thermal stability at the operational temperature imposed by theexpanding vapor. The outermost edges of the tips of blades 6 a can bemade of a sealing material (i.e. Teflon), which becomes softer when itscross section is sufficiently thin, offers good lubricatingcharacteristics, and forms a good seal between the rotating parts of thewheel and the static casing 1. The shape, the height, and angles of theblades 6 a of the EW are designed such that the maximum torque isobtained at a desired RpM, thereby matching the optimum RpM of the airCW 2 a, inside the diffuser 2. EW 6 is also co-axial with the EGW 3 b,and the CW 2 a. All of the wheels 6, 2 a, and 3 b are mechanicallycoupled to the same shaft 12 pressure-sealed in various points (not allshown in FIG. 1) by a series of o-ring seals 93 or similar. Inside theexpander block 1, there is at least one thrust bearing(s) 4, and/orfluid lubricated bearings 5 of conventional design, or of special designas described in FIG. 4. To achieve a good thermal insulation between theexpander casing 1, and the air compressor sections formed by the CW 2 a,and casing 2, a thermal seal 18 is positioned between the compressorparts and the expander body 1. In this configuration the thermalinsulation 18 is necessary to prevent heat from the expander from beingtransferred to the compressed air inside diffuser 2.

In FIG. 2, expander 1 is shown in detail. The superheated vaporgenerated in the converters described in FIGS. 5, 6, 15, 16, and 18enters inlet 9 (FIG. 2) which can be positioned symmetrically withrespect to shaft 12 of FIG. 1, or they can be positioned anywhere on theexpander body 1. If water is the working fluid of the MWHE (any fluidwith the proper thermodynamic, and physical properties could beutilized), superheated steam at a desired pressure and temperatureenters inlets 9 and flows through nozzles 17. Nozzles 17 can be simpleconverging static nozzles, designed to obtain a desiredpressure-to-velocity conversion, or they can be actively actuated orstatically tuned through means 15, 14, and 13. These means allow thepressure and velocity of the steam to be finely adjusted before itexpands through blades 6 a of EW 6. Regulation means 14 consists of amechanical link able to insert or withdraw a special needle 13. In thismanner the expander can be customized to operate at an optimum speed asa function of the mass flow rate and thermodynamic properties of steamentering through inlets 9. Nozzles 17 are positioned inside the body ofthe expander 1 in a way that the forces generated against blades 6 acounterbalance the forces acting on the shaft 12 (FIG. 1). This reactionforce is proportional to the mass of steam impinging on the blades 6 a.Once steam expanded though EW 6 it can exit expander 1 though thedischarge paths 10 which are hydraulically connected to acondenser/radiator 86 shown in FIGS. 17, and 17A. Lubrication ofbearings 5 is accomplished through an oil tank 16, oil paths 16 a, and16 b, and a sump tank 16 c. The lubrication methods can utilizeconventional designs via forced circulation of oil through an externalpump, or through an innovative method shown in FIG. 4. Expander 1 canalso be designed such that bearings 5, and the hydraulic oil paths 16 a,and 16 b, are not integrated inside the expander body (for example,bearings 5 could be positioned inside blocks 2 and 3 of FIG. 1). Tominimize heat and pressure losses between the EW 6 and the static blockof expander 1, a series of proper seals (o-ring, graphite, etc.) can bepositioned as indicated by number 93. As an additional sealing meanbetween the blades 6 a and the static components of expander 1, a Tefloncoating of the volume surrounding the wheel and on the EW 6 itself canbe utilized. For example, if the wheel is made of Teflon, the tip of theblades can be molded (or machined) such that the flexibility of Teflonis utilized as a centrifugal seal. Then, a flexible portion of theblades, at the edge of the blade's tip, rubs against the casingcontaining the wheel. Since the casing is Teflon coated from the inside(or a Teflon ring is positioned around the wheel) the overall structurebecomes sealed although the wheel is rotating and the case is static.Furthermore, the optimum lubricating characteristics of Teflon allow theseal to last a significant amount of time; however, any other sealingcompound could achieve the same results. To minimize heat transfer fromthe expander body to the compressor body a thermal seal 18 is utilizedas shown in FIG. 2. The material of this seal has very low thermalconductivity.

In FIG. 3, the transfer of heat between the expander body 1 and thecompressor body is instead favored. In this configuration steam exitsthe blades 6 a and enters a condensation chamber formed by a hydraulicpath defined by fins 19 and 20. In this manner, relatively cold airpassing through the compressor cools down the surfaces of thecondensation chamber and vapor implodes instantaneously. When steamsuddenly condenses (implodes), immediately after its expansion throughthe blades of EW 6, it causes a steep pressure drop which increases theoverall expander efficiency. The choice between an expander 1 c of FIG.3, or 1 of FIG. 1 is mainly based on a compromise between the desiredair compressor efficiency and the efficiency generated by thecombination of the various waste heat converters. In FIG. 3, steamenters the expander 1 c from inlets 9 (here shown in a non-limitingsymmetric configuration) passing through nozzles 17 where itsthermodynamic characteristics in terms of pressure and velocity areadjusted actively or statically. Then, it expands through blades 6 a andenters a forced cooling hydraulic path formed by fins 20 and 20 a. Fins20 a have the purpose of extending the cooling surface area formed byfins 20 a of component 19 in contact with large mass flow of thecompressor intake air. As soon as steam enters in intimate contact withthe surfaces 19, cooled by air, steam contracts suddenly changing itsspecific volume of a factor greater than a thousand. This sudden changein specific volume inside a system where the system volume is fixedprovokes a steep drop in the local pressure. Decreasing the pressure atthe discharge of blades 6 a is equivalent to increasing the pressure atthe exit of nozzle 17, thereby obtaining more thermodynamic work at theshaft of the expander (i.e. 12 in FIG. 1). Since the air flowing on theoutside of the expander could be the same air/oxygen being compressedinside the engine intake manifolds, the temperature of the compressedair increases consequentially. However, since the mass of steam to becondensed is minimum with respect to the mass of air flowing inside thecompressor side, the increase of air temperature is minimum, therebyaffecting the air compressor efficiency only marginally. In other words,the pressure drop caused by the forced steam implosion causes anincreased expander efficiency, while the consequential air temperatureincrease causes a lower compressor efficiency. However, the overalldevice efficiency increases since the gain in expander efficiency isgreater than the loss of the compressor efficiency. In FIGS. 3A, and 3Bthe expander bodies 1 c and 1 of FIG. 3 and FIG. 2 are shown side byside to show their major differences. In FIGS. 3A, and 3B, the controlof the EW 6 velocity is executed in a dynamic manner (active control),through means 13 able to adjust the diameter of nozzle 17 and controlthe thermodynamic properties of steam flowing through nozzle 17 viacomputer/controller 92, described in FIG. 17, or through a specializedsub-computer system, indicated by “S”. Sub-computer system S, is aspecialized controller which optimizes the operation of a particularsub-component of the miniaturized engine (in this case the expander).Sub-computer system S can be interfaced with the computer 92 describedin FIGS. 17 and 17A. Needles 13 are continuously re-positioned/adjustedthrough the servo mechanisms driven by motors 112. Motors 112 can bedriven by electricity or be activated by pneumatic means. The basiccontrol of EW 6 speed is executed via detection of the wheel speedthrough a movement sensor 115 (i.e. Hall effect sensor) connected to thecomputer 92 of FIG. 17. Computer 92 monitors the whole thermodynamiccondition of the expander and heat converter(s) and adjusts the positionof needles 13 proportionally to the amount of steam available, itsthermodynamic state, the speed of the wheel and so forth. In thismanner, EW 6 is always operated under optimum conditions.

In FIG. 4 a preferential hydraulic circuit for the lubrication of shaft12 is shown. In FIG. 4, bearings 5 are represented in a non-limitingmanner inside the body of the expander. Bearings 5 can be formed bybushing materials lubricated by the rotating action of shaft 12. Oil 24,or a lubricating fluid, inside tank 16 flows inside the hydraulic paths16 a and 16 b forming inner channels and undergoes an accelerationthrough embedded blades 22 etched on the surface of shaft 12. In thismanner, oil 24 gains kinetic energy inside blades 22 and converts thisenergy into potential energy. For example, oil molecules 24 (FIG. 4 topright), enter channel 16 a and flows inside the internal blades 22 onshaft 12. Blades 22 are shaped in a way that the rotation of the shaftimparts acceleration to the oil as soon as the shaft reaches minimumspeeds. In this manner the velocity at the end of channel 16 b is higherthan that at the entrance of channel 16 a generating a pumping effect.Since shaft 12 rotates at reasonably elevated RpM, even a slight angleof blades 22 causes a desired pumping effect. Therefore, oil 24 insidetank 16 is forced by a depression in channel 16 a to go through blades22, lubricating the bushing or bearing 5 and returning back to tank 16through channel 16 b. In other words, lubrication of shaft 12, bearingor bushing 5 occurs as an automatic result of the rotation of shaft 12.The higher the number of revolutions per minute of shaft 12, the moreoil is pumped through blades 22, therefore lubrication and coolingeffects increase with increased shaft rotational speeds automatically.In general, blades 22 can be formed by micro-channels properly shaped onthe surface of shaft 12 or 12 b. The number of blades 22 can be even orodd as long as symmetry and/or balancing of shaft 12 or 12 b isrespected. The oil paths from tank 16 to the various bearings 5 can bemade such that each bearing has its own oil inlet and outlet. Oil inlet16 a could be located at the inlet of one set of bearings 5 (FIG. 4,bottom), be accelerated by a first set of inner blades 22, flowinginside shaft 12 b through hole 23 a into channel 23 inside the shaft,entering the suction side of inner blade 22, through hole 23 b, andfinally being discharged into channel 16 b which returns the oil back totank 16.

In FIG. 4A, the effect of the forces developed by the action of the EGW3 b, CW 2 a, and EW 6 is represented. A solution to the wearing of thethrust bearing is now described. Thrust bearing 4, which can bepositioned anywhere along shaft 12, normally has to counterbalance thereaction forces developed by the EGW 3 b and the CW 2 a. These forcesare developed as a reaction to the motion of the exhaust gases and airon the blades of the wheels. When EW 6 of the vapor expander isintegrated inside the body of the overall device (for example as shownin FIG. 1), it is possible to position nozzles 17 such that the reactionforces developed by the steam on the blades of EW 6 counter oppose theeffect of the forces generated by all other wheels (i.e. 3 b and 2 a,FIG. 4A), thereby minimizing the wearing effect on the thrust bearing 4.By positioning and properly dimensioning nozzles 17, the net vapor force118, indicated by F_(vapor), could be of the same magnitude and oppositedirection of forces 116 and 117 generated by wheels 2 a and 3 b andindicated on the vector diagram (FIG. 4A, top) as F_(air) and F_(gas).In fact, by assigning a positive sign to the forces from left to right,F_(vapor) is positive, while F_(air) and F_(gas) are negative (thevector notation is not necessary since they all move about the sameaxis). By properly dimensioning the diameter of nozzles 17, along withthe proper dimensioning of the waste heat converters, and the diameterof EW 6, it is possible to generate a reaction force 118 resulting fromthe momentum generated by the expanding steam. In FIG. 4A, the directionof the forces represented is only indicative. If the expander isutilized only as an independent oxygenator (i.e. FIG. 8), EW 6 operatesat constant RpM, (particularly the case for applications described inFIGS. 11, 12, and 13), therefore, it is possible to adjust the reactionforce of the vapor (F_(vapor)) in a way that the axial forces acting onthe thrust bearing are zeroed.

In FIG. 4B the expander is coupled with a flipped CW 2 a (details ofthis configuration are described in FIGS. 8 and 9), and it is equippedwith a balancing system which acts on the rotating masses and adds itsown weight as a force opposite to the reaction force 116 of the CW 2 a.Even in this case the proper dimensioning of the EW 6, along with theproper overall MWHE thermal properties, and the correct positioning ofnozzles 17 inside the expander body can minimize the effects of thereaction forces caused by CW 2 a and acting on thrust bearing 4. In thisconfiguration the CW 2 a is positioned in a way that it forms 180° fromthe position of the same wheel utilized in conventional centrifugalcompressors. In this case, the axial component of the forces acting onthrust bearing 4 is mainly made by force 116 generated by thecentrifugal compressor itself (pushing shaft 12 upward). If the body ofthe oxygenator (30, in FIG. 8) is positioned vertically, then nozzles 17in FIG. 4B can be positioned such that the summation of the forcesgenerated by the weight of shaft 12 (times the force of gravity, “FG”),the weight of the balancing mass 120 and 121 (times FG), generatingforce 119, and the resulting force 118 caused by the steam reaction onthe blades of EW 6 could be exactly equal and opposite to force 116,thereby zeroing its effect. Similarly, if we significantly increase mass120, or we utilize a heavy CW 2 a (i.e. obtaining a flywheel effect),nozzles 17 can be positioned in a way to favor the effect of force 116.Balancing mass 120 and 121 also provides means to adjust the usualoff-balance components of shaft 12, coupled with the various wheels. Infact, mass 121 can be moved from its central position through screws 122and blocked in place by screw 123. The mass system formed by masses 120,122, and 123 can be positioned anywhere along shaft 12 (the dimensionsrepresented in FIG. 4B are not scaled). In this manner the balancing ofthe whole rotating system (i.e. shaft 12, CW 2 a, EW 6, and eventuallyEGW 3 b) can be executed once the unit is assembled.

An integrated vapor expander 1 a positioned inside the components of aconventional turbo-compressor is shown in FIG. 5. In this Figure,expander 1 a is formed by a special Multiple Stage Wheel, “MSW,” 7,characterized by a series of blades 7 a, 7 b, and 7 c, assembled molded,or machined inside the same wheel. Steam enters expander 1 a throughinlet (or inlets) 9 d positioned on the body of a special jacket 25containing the bodies of the centrifugal exhaust gas nozzle 3 a and theEGW 3 b. Steam is provided at the desired temperature, pressure, andmass flow rate by the converters described in FIGS. 15, 16, 17, and 18.Again, steam enters at inlets 9 d, receives additional heat mainly byconvection and radiation inside the heat chambers formed by the surfacesof nozzle 3 a and jacket 25, and plows inside the expander body 1 a. Tominimize heat losses, insulating materials can be utilized, or a vacuumchamber can be formed by evacuating the air inside another chamberformed by the surfaces of jacket 25 and those of an additional jacket 25a. Air can be extracted during manufacturing, or through a vacuum valve124. Superheated steam now enters the expander body 1 a and expandsthrough the first set of converging nozzles 17 (the drawing issymmetric). The exit diameter of nozzle 17 is designed to transfer themaximum momentum to the first set of blades 7 a of MSW 7. Again nozzles17 can be fixed or actively adjusted as shown in FIGS. 2 and 3.Normally, steam exiting this first stage of blades (7 a) would enter anew stage of blades on a new separated wheel designed to match the newsteam properties. In this invention a new series of blades 7 b is stillpositioned on the same wheel (MSW 7), but has a different diameter and adifferent shape to compensate for the changed steam direction and itsvaried thermodynamic state. Therefore, steam loses a fraction of itsenergy by expanding through blades 7 a, it then enters a new set ofnozzles 17 a (fixed or actively adjusted) after having changed directionby 180° through a polished elbow inside the body of expander 1 a. Now,steam at certain thermodynamic conditions expands through the new set ofblades 7 b. Another converging nozzle 17 b provides the properadjustments in terms of steam pressure and velocity, since steam losesmore and more energy as it expands in the various stages. Exiting nozzle17 b, steam expands again inside another set of blades 7 c positioned onthe periphery of MSW 7. Finally, the exhausting steam is removed fromexpander 1 a through the discharge hydraulic paths 10, or through animploding chamber (not shown) as described in FIG. 3. Therefore, thetechnique of turning the steam flow path of 180° allows the generationof more torque from the same wheel instead of three or more, therebyreducing weight, inertia, and allowing a significant miniaturization ofthe expander body. The lubrication system of expander 1 a can be formedby a conventional oil lubricating system, through an external pump, orby a system that utilizes bearings 5 as described in FIG. 4. If thelubrication system is similar to that described in FIG. 4, the oil, oran equivalent lubricating fluid, can be cooled through tanks 16 c,assembled on the diffuser body of the air compressor. Since the maximumtemperature of the air at the discharge of the CW 2 a is only 1.5 to 2.5times the air inlet temperature (generally below 40° C.), this sectionof the overall device can provide proper cooling for the lubricatingfluid. To minimize heat losses from the expander body 1 a to the airflowing inside the compressor, a thermally insulating seal 18 ispositioned as a buffer between the two different bodies.

FIG. 6 represents an expander integrated inside the body of aturbo-compressor with characteristics similar to those described in FIG.5. In this Figure the steam flowing inside the heat chamber formed bysurfaces 3 a and 26 e occurs in a way that it can flow in and out theheat chamber independently of inlets 9 e of the expander body 1 a. Theheat chamber is also thermally insulated by vacuum through valve 124, orby utilizing thermally insulating materials coating, or covering theexternal surfaces 26 e (i.e. thermal blanket 25 b). In thisconfiguration, steam is superheated to certain temperatures, and thencan be forced inside another heat converter to reach even highersuperheating temperatures.

FIG. 7 represents MSW 7 with more details. To conserve the desireddirection of rotation indicated by 27, the inclination/shape of blades 7a, 7 b, and 7 c changes in each stage. As shown in FIGS. 5 and 6, steamenters inlets 9, accelerates inside nozzle 17 and expands in the firstseries of blades 7 a whose shape is designed to transfer the kineticenergy of the steam into mechanical energy at the shaft of the wheel.The shape of blades 7 c, 7 b, and 7 a, represented in the drawings ofFIG. 7 is only indicative. Now, steam exhausting blades 7 a isredirected and enters a new nozzle 17 a to expand through blades 7 b.The inclination of blades 7 b is different than that of blades 7 a sothat the rotational direction 27 is conserved. Finally, steam exhaustingfrom blades 7 b is redirected again and conditioned by nozzle 17 bdesigned to convert low pressure steam into kinetic energy, and expandsthrough blades 7 c. At this point, the steam energy content is low andit can be discharged into condenser 86 (FIG. 17 or 17A). Each series ofblades 7 c, 7 b, and 7 a is connected to the MSW 7 through sections 26and 26 a. The number of sections 26 and 26 a can vary proportionally tothe diameter of the wheel, the mass flow rate of steam, and the torquerequired.

An innovative centrifugal compressor (oxygenator)—completelysymmetrical, easy to manufacture and utilizing simpler parts—is shown inFIG. 8. Again, the oxygenator is one of several sub-component of theMWHE. In this case, expander 1 a is mechanically connected to a CW 2 aassembled 180° rotated with respect to shaft 12. This configurationallows symmetry of the mechanical parts (easier to assemble andmanufacture) and provides higher compressor efficiencies. Air flowsthrough air path 40 and through an axial diffuser 29, entering the bodyof CW 2 a and gaining kinetic energy as a result of the centrifugalaction of the wheel. Air exits with the maximum energy at the tip of CW2 a's blades, and enters a diffuser specially shaped as indicated byregion 95 in FIG. 8. This diffuser is symmetric and divergent along thewhole length of body 30. The first transformation of the kinetic energyof the air into pressure occurs in region 95, and further gain inpressure occurs along fixed blades/vanes 31 regularly spaced on a fixedcone 33. The shape of vanes 31 is such that the turbulent motions andvortexes of the air at the exit of CW 2 a (blades tip) are reorganized,redirected and converted into pressure (useful energy). Furthermore, thecross section of the diffuser formed by cone 33 and the internalsurfaces of body 30 makes a diverging nozzle. In fact, the cross sectionradially changes from small to large, as shown by distances d1 and d2,indicated by number 32. In this manner another component of the velocityof the air exiting the CW 2 a is converted into pressure. Body 30 ismechanically linked to the expander 1 a through coupling flange 28. Cone33 and vanes 31 are static and fixed to body 30. To summarize, the bodyof the oxygenator is formed by two concentric cones having differentheight and diameter, or by a cone concentric and internally positionedinside a cylinder able to provide characteristics similar to thosedescribed by body 30. Flange 28 can be linked with body 30 throughadditional static fins/vanes (directing the air flow into CW 2 a), orthrough an open semi-toroid body 39 surrounding the inlet of theoxygenator and providing the structure for the intake manifold 40.Manifold 40 can be easily connected to a conventional air filter. Theoverall device formed by the expander 1 a and body 30 forms anoxygenator which can be designed to provide a minimum mass flow ofoxygen sufficient to allow complete combustion from idling IC engine RpMto medium high RpM. If the outlet of the oxygenator 40 a is connected toan engine intake air system equipped with a conventionalturbo-compressor, membrane valves 38 could automatically open every timethe pressure in the region adjacent the vortex of cone 33 is belowatmospheric pressure. Therefore, the oxygenator could be designed toprovide oxygen at low RpM, while the conventional turbo-compressor wouldstart to operate properly at high RpM, so that the by-pass valves 38allow the turbo-compressor to breathe even if the oxygenator is notdimensioned to provide the full range of mass of air at high engine RpM.By-pass valves 38 are formed by membrane 35 composed by flexiblematerials (i.e. rubber, composite) with the proper thickness,dimensions, torsion and physical properties. One by-pass valve 38 withthe proper hydraulic diameter (effective cross section seen by thefluid), or more valves with equivalent air flow characteristics can beassembled on body 30. In general, expander 1 a, 1 (or 1 b as describedin FIG. 14), can provide the propulsion necessary to CW 2 a. If theexpander is properly miniaturized it can also be inserted inside thebody of cone 33, as indicated by dashed box 1 c. In this case, steaminlet paths 9, and steam discharge paths 10 can be made through thethickness of vanes 31. Steam paths 9 embedded inside fins 31 would bethermally insulated, while the steam exhausting from EW 6, or MSW 7,would be exposed to the air-cooled surfaces of cone 33 and vanes 31.When the steam exhausting EW 6 or MSW 7 impacts the cold internalsurfaces of cone 33 it suddenly condenses (implodes), generating apressure drop which increases the overall oxygenator efficiency. Thisoxygenator can also be coupled with a conventional EGW 3 b (and relativenozzle) by unplugging thermal plug 41 and extending shaft 12. In otherwords, by prolonging shaft 12 it is possible to add pulsed propulsion tothe CW 2 a by utilizing the kinetic energy of the exhaust gases.Expander 1 a shown in FIG. 8 (or even expanders 1, or 1 b) can actuallybe miniaturized to a point that it can be inserted inside the conestructure of the symmetrical oxygenator. In this case, the oxygenatorbody 30 would contain cone 33 and inside cone 33 the expander 1, 1 a, or1 b. Then vanes 31 would contain hydraulic paths for the inlets 9 ofexpander 1 a, and hydraulic paths for the vapor discharge 10. The inlethydraulic paths 9, now embedded inside vanes 31, would be thermallyinsulated, while the discharge paths 10 are allowed to transfer heat andcondense inside the hydraulic paths 10 (embedded inside vanes 31), sincevanes 31 are always at low temperatures due to the action of the massflow of air. By creating an implosion chamber inside cone 33, thesurfaces of the cone provide the cooling surfaces for superheated vaporto suddenly collapse when in contact with the inner surfaces of cone 33.In this case, the symmetric oxygenator becomes extremely compact sinceits expander and implosion systems are all contained inside body 30.Furthermore, when a complete implosion occurs inside body 30 there is noneed to circulate the vapor inside a condensing radiator (i.e. 86 inFIGS. 17, and 17A), thereby further simplifying the miniaturized enginehydraulic path and connections.

Another symmetric oxygenator, similar to that described in FIG. 8, isrepresented in FIG. 9. In this oxygenator, air enters the body of CW 2a, passing diffuser 29, in a radial manner (from every direction). Inthis configuration a cylindrical air filter can be positioned betweenbody 30 and flange 28 a. To improve the efficiency of the CW 2 a, staticvanes can also be positioned inside the intake path 96. However, theoxygenator can also provide oxygen to the engine without an air filterassembled on itself (see FIG. 11). In general, EW 6, MSW 7, and CW 2 a,can be made of plastic, Teflon, composite, metal or any material whichmaintains its thermal-physical properties for relatively lowtemperatures (much lower than the exhaust gases temperatures). If theMWHE is applied to a large IC engine, the amount of heat generated bythe engine, recuperated by the converters, and transformed back intouseful energy by the MWHE's expanders is much greater than the energyrequired only to power the oxygenators. Thus, the excess energy can beutilized in various ways. For example, it can be utilized to provideadditional mechanical power to the IC engine itself.

In FIG. 10, an auxiliary pulsed or continuous power transferring systemformed by the Auxiliary Expander Flywheel AEF 11 is shown. In thisfigure, the power unit comprised by body 42 is directly connected to theIC engine block 43. In general, power unit 42 can be connected to anyload (i.e. an alternator for the production of electric power). In FIG.10, the excess steam enters hydraulic paths 9 c, and expands through theblades of AEF 11. AEF 11 is made of heavy materials to provide a largerotational inertia. Steam enters nozzles 17 c and discharges intocondensation chamber 51. A fraction of the steam condenses in thischamber; the remaining steam (steam with a low energy content) exits thepower unit 42 through paths 10 b and condenses in a condenser. Bycooling chambers 51, the steam implosion effect described in FIG. 3 canbe utilized to increase the efficiency of AEF 11. A speed reductionsystem formed by gears 49 and 50 may be necessary if the optimumefficiency of the AEF 11 is obtained at high RpM. The optimum parametersare mainly dictated by the amount of excess steam available and the gearreduction system might not be necessary if AEF 11 operates at RpMcompatible with the IC engine RpM. AEF 11 is mechanically coupled to theIC engine crankshaft 44 by a modified pulley 45. The modificationconsists of a flange 46 mechanically linked to another flange 47 coupledto a clutch system 48. Clutch 48 can be hydraulic, magnetic, frictionbased, or a combination of any of these depending on the desired degreeof accuracy when transferring power from the power unit 42 to the ICengine (or any load). For example, clutch 48 can be formed by oil whoseviscosity at a given RpM provides the desired frictional torque. If anelectronic clutch is utilized, sensor 55 monitors the speed ofcrankshaft 44, while sensor 56 provides analog or digital information onthe speed of AEF 11. The electronic signals from these sensors becomeinputs (i.e. 135 FIGS. 17, and 17A) of a computerized control system (92FIGS. 17 and 17A) which activates clutch 48 in a pulsed or continuousmanner. In order for AEF 11 to provide power with the best efficiency,only a relatively small fluctuation of the AEF RpM should be allowed.Therefore, by utilizing the power provided by power unit 42 in a pulsedmanner, the RpM of AEF 11 could vary only slightly. To minimize heatlosses from the power unit 42, a thermally insulating material 54 coversthe static parts of AEF 11.

FIG. 11 represents one of the simplest applications of the oxygenatorunit 30. In this Figure, the outlet of the symmetric oxygenator 30 isconnected to the air filter inlet 60 positioned on the body surroundingair filter 59. Large IC engines normally have the air filter inletformed by a tube vented to atmospheric pressure. The expander of thisoxygenator could be of type 1 a, 1 or 1 b. The oxygenator shown in FIG.11 utilizes expander type 1 a. By applying the oxygenator as shown inthis Figure, the whole engine air intake system is always pressurizedwithout altering in any way the conventional turbo compressor 2 and 3already installed. Air enters the protective filter 57 from alldirections. Then it is compressed inside the air filter 59 whichpressurizes the intake manifold 61 and 63 regardless of the IC engineRpM, or the status of compressor 2. When the IC engine accelerates, thesudden increase of fuel injected mixes with excess oxygen (thanks tooxygenator 30), providing a complete combustion and an extremely rapidresponse without producing toxic particulate and other pollutants duringacceleration. If expander 30 is intentionally under-designed (not ableto provide large mass flow rates once the IC engine reaches high RpM),the conventional compressor 2 gradually starts to compress air on itsown (the IC engine is accelerating from idling to high RpM), therebyprovoking a depression inside manifold 62, 61 and 60. As soon as thepressure inside manifold 60 is below atmospheric, by-pass valves 38open, providing an easier path for air to flow inside compressor 2 nowat full regime. Steam inlet 9 b and outlet 10 are connected to aconverter and a condenser, respectively (as seen in schematic in FIGS.17 and 17A). Since the expander unit 30 could accommodate for anadditional EGW connected to its shaft, a plug 41 is inserted wheneverthis option is not utilized. If the oxygenator unit 30 breaks down, theIC engine operates as it did before the oxygenator was installed,thereby without impairing the IC engine (it would just decrease itsperformance and pollute again).

FIGS. 12 and 13 show the oxygenator unit 30 inserted inside the intakemanifold circuit. In these configurations, the compressed air exitingthe accelerating nozzle 64 or 66 is air filtered by filters 59, or 59 a.Pressure inside the intake manifold is increased thanks to the jeteffect caused by nozzle 64 or 66. Again, thanks to the oxygenator,powered by MWHE, oxygen is always available to the IC engine regardlessof its RpM. Again, if the oxygenator is intentionally under-designed,the proper mass flow rate to the suction of compressor 2 is providedby-pass valves 38. When the oxygenator is configured as shown in FIG.13, nozzle 66 provides a more efficient output of oxygen to the intakemanifold 67. To make the oxygenator air inlet completely independentfrom the IC engine air filter 59, an additional and independent airfilter 59 a can be connected to oxygenator 30 through a sealedconnection to inlet 40.

To summarize the various expander-to-compressor configurations, a seriesof oxygenator units are shown in FIG. 14. From left top, expander 1 ashows the ease with which the expander body 1 a can be coupled withbodies 2 and 3 of conventional CW 2 a and EGW 3 b. In particular, theexpander wheel can be conventional (i.e. EW 6) or the MSW 7 described inFIG. 7. For example, expander body 1 of the oxygenator unit representedat the top center of FIG. 14 utilizes EW 6, while expander 1 b utilizesa series of expander wheels 8 for a conventional multiple stage steamexpansion. In any case, all of these expander units can be mechanicallyintegrated between the compressor and exhaust gas units normallyavailable. The miniaturization of the expander body 1 a, 1 and 1 ballows also coupling with a convention compressor unit 2 and 2 a so thatoxygen can always be provided to the IC engine independently of ICengine RpM. For example, the oxygenator unit shown at the left bottom ofFIG. 14 describes an expander unit 1 a able to provide steam propulsionto a commercial CW 2 a, while the shaft of the unit is truncated on oneside allowing the insertion of plug 41. This particular configurationcan be utilized for the applications described in FIGS. 11, 12 and 13.The oxygenator represented at the bottom center of FIG. 14 is the mostoptimized oxygenator unit since it utilizes symmetric geometry andcompletely converts vortexes and kinetic energy of the air intopressure. This unit is formed by combining body 30 and 1 a, or body 30and 1, or body 30 and 1 b. In general, a symmetric geometry can beconserved even if the various expander bodies are embedded/integratedinside the cone contained inside body 30. Finally, the oxygenator shownat the bottom right of FIG. 14 is another oxygenator configured in a waythat air enters through an inlet manifold 40 and can flow through aby-pass path 37 c, and by-pass valves 38. This configuration isparticularly useful when the IC engine is already equipped with aturbo-compressor, or turbo-charger, and the oxygenator only needs toprovide oxygen at idling and low IC engine RpM, while theturbo-compressor already installed provides compressed air at high RpM.All of the oxygenator bodies are designed in an universal manner so asto allow for connections of additional EGW 3 b, and casing 3, byremoving plug 41 and inserting a proportionally dimensioned shaft.

The heat converters of the MWHE are shown in FIGS. 15, and 15A. Liquidwater (or the proper thermodynamic fluid) is injected at about 70-80° C.through a pump (pump 87 shown in FIGS. 17, and 17A). Then, high pressurefluid is injected via injector 69 connected to hydraulic path 68. Thisinjector can essentially be a check valve, spring loaded, orelectronically activated. If the pump is a positive displacement pump,injector 69 can actually be eliminated. Liquid fluid is now injectedinside the heat converter formed by body 70 within which hot exhaustgases 80 flow and are vented to atmospheric pressure. The amount ofenergy transferred from gases 80 to the fluid inside the converterdepends mainly on the fluid-converter contact surface, length d3, andmass of MWHE fluid injected. To favor a greater heat exchange betweenfluid and gases inside converter 70 a series of helicoidal surfaces 71are inserted inside the converter. These surfaces prolong the fluidresidence time inside the converter by extending the hydraulic path ofthe fluid before it exits outlet 72. The working fluid (i.e. water)expands inside the converter, accelerates by moving through thehelicoidal surfaces 71, and becomes superheated vapor or superheatedsteam. Because of the explosive nature of the expansion of the fluidinside the converter, the relative heat transfer coefficient increasesaccordingly, thereby allowing a miniaturization of the converter itself.Thus, superheated steam, at certain thermodynamic conditions, is nowavailable at outlet 72 (FIG. 15). Further superheating of steam can beachieved by connecting outlet 72 to a series of superheating channels 73in thermal contact with the exhaust gases. The maximum superheatingtemperature of the steam is reached inside channels 73 closer to thecombustion chambers outlet (near the exhaust manifold flanges 74).Channels 73 can be substituted by a jacket surrounding the exhaustmanifold becoming another converter. To regulate the excess steam athree-way valve 77 is connected to tube 76 exiting the converter formedby channels 73. In general, valve 77 can be substituted by equivalentvalves 77 a, and 77 b as shown in FIG. 17. In FIG. 15 the oxygenatorunit is integrated with a turbo compressor as described in FIGS. 5 and6, and is thermally insulated by insulating material 25 a. Valve 77 isoperated to control the admission of steam inside the expander unit, andto redirect the excess steam to the AEF 11 (FIG. 10) through thehydraulic path 79. Outlet 78 of valve 77 is connected to the expanderinlet ports 9 d (or 9 d, FIG. 5, and inlet/outlet ports 9 d, FIG. 6).Superheated steam expands inside the integrated expander (1 a, 1, or 1b), and condenses into a condenser through discharge hydraulic path 10,or it condenses through implosion inside the body of the expander (FIG.3). To minimize heat loss from the exhaust manifold 74, an insulatingmaterial 75 can be utilized as shown in FIG. 15. Seals 94 between ICengine block and exhaust manifolds 74 are made of a thermally insulatingmaterial as well (conserving heat of the exhaust gases). To preventoverheating of the converter formed by channels 73 in thermal contactwith the exhaust gases near the combustion chambers outlet, thethermally insulating structure 75 can be arranged in a way that movablefins 134 (FIG. 15A) opens when the MWHE is malfunctioning. Therefore,activating fins 134 in FIG. 15A provides cooling of the exhaust gasmanifold structure when steam is not circulating inside the MWHE. InFIG. 15A, the thermal insulation 75 described in FIG. 15 can be formedby an air chamber relatively sealed when fins 134 are closed (when theMWHE is working properly), or thermal insulation is minimized when fins134 are automatically or manually opened (air can circulate through theexhaust manifold). For example, opening of fins 134 can occur if thetemperature of the manifold materials overcomes a pre-set safetythreshold.

In FIG. 16 a higher degree of steam superheating can be achieved thanksto different hydraulic connections of the various converters. Again,liquid fluid is injected through injector 69, becomes superheated at themax temperature of converter 70, exits from outlet 72 and enters theconverter formed by the jacket surrounding the EGW 3 b through inlet 9d. Here another energy transfer process occurs and the superheated levelis increased. Superheated vapor exits this converter from outlet 9 d andenters the converter formed by channels 73. Here the level of superheatis increased even further. Now, vapor at its maximum temperature andpressure is regulated by valve 77. The excess vapor is directed towardthe AEF 11 via thermally insulated tube 79, while the proper amount ofsuperheated vapor is allowed to expand inside the expander throughthermally insulated tube 78, connected to expander inlet 9 e. Vaporgives up energy through the expander and condenses into a condenser viatube 10. The exhaust gases 80, generated during combustion, transferheat to the various converters (channels 73, jacket surrounding EGW 3 b,and converter 70) while also transferring their kinetic and pressureenergy to EGW 3 b (blanketed by insulation 25 b in FIG. 16). Oxygen, onthe other hand, enters the air intake manifold 81 and is compressed byCW 2 a, surrounded by structure 2. CW 2 in this configuration is poweredby the summation of the torque developed by the MWHE's expander(especially at low IC engine RpM), and the torque generated by the EGW 3b, once the IC engine reaches relatively high RpM. The variousconverters utilized in FIGS. 15 and 16 can be utilized in theapplications described in FIGS. 11, 12, 13 and 14.

Finally, thermodynamic processes of the complete MWHE are described inthe schematic in FIG. 17. The cooling circuit of the IC engine 43 isformed by the closed hydraulic loop composed of the water pump 82,radiator 84, and converter 83. The cooling water of IC engine 43normally reaches 90° C., after which a thermostat valve, usuallypositioned at the discharge of pump 82, opens and allows a forcedcirculation of the coolant to the radiator 84 which transfers heat viaair convection indicated by arrow 85. By inserting the heat converter 83and 83 a, most of the heat carried by the coolant can be transferred toa new closed hydraulic closed loop. Converter 83 and 83 a separates theIC engine cooling circuit from the MWHE circuit for safety andreliability. However, this converter can be eliminated if the MWHEworking fluid is also utilized to cool the IC engine 43. In this case,radiator 84 becomes the condenser 85 of the MWHE, thereby simplifyingthe overall device. If the hydraulic circuit of the MWHE is independentof that of the IC engine 43, a different fluid (i.e. with lower vaporpressure inducing higher thermodynamic efficiencies) can be utilized asthe working fluid for the MWHE. The working fluid circulating inside thecircuit of the MWHE is pressurized by pump 87 and receives a first heataddition process inside side 83 a of the converter formed by the twoseparate loops 83 and 83 a. This pressurized fluid is then injectedthrough hydraulic path 68 and injector 69. Converter 88, represented inFIG. 17, can be formed by the combinations of the converters formed bybodies 70, 73, 75, 25 a and 25 b, and the converter formed by the jacketsurrounding the EGW 3 b in FIG. 15, 16, and/or converter 103 describedin FIG. 18. Back to FIG. 17, liquid fluid enters converter 88 andexpands immediately. At the outlet 76, a superheated desired mass ofvapor, with a certain energy content, is regulated by valves 77 a and 77b (or a three-way valve 77, FIGS. 15, and 16) so that the proper amountof steam is admitted by expander 1 and AEF 11. Expander 1, provides thepropulsion system for a compressor system 2, or any of the oxygenatorsdescribed in FIG. 14. AEF 11 instead utilizes the excess steam totransform it into useful energy by direct or indirect coupling withcrankshaft 44. Pressure and temperature sensors are positioned insideconverter 88 providing thermodynamic information via electronic signals91 processed by a computerized unit 92, or a sub-computer system,indicated by “S” in the drawings, specialized only to optimize theoperation of one of the miniaturized engine sub-components (i.e.,expander, imploder, converter). Computerized unit 92 monitors andcontrols the amount of steam to the various expanders throughactuators/valves 89. For example, actuators 89 can be electrical motorsor pneumatically actuated motors that regulate valves 77 a and 77 b.When the IC engine 43 is cold started, computer 92 activates pump 87through the electric connection 90 only when the temperature ofconverter 83 or converter 88 reaches a pre-set level. Pump 87 could alsobe entirely mechanical (i.e. positive displacement) and activatedthrough mechanical links by the IC engine 43. Again, when pump 87 isactive, the fluid receives heat from converter 83 a before beinginjected inside converter 88. Inside converter 88 pressure andtemperature of the rapid forming vapor is proportional to the amount ofheat transferred from exhaust gases 80. All of the expanders (i.e. 1 a,1, 1 b, 11) utilized by the MWHE are controlled by computer 92 and canbe operated in a pulsed or continuous manner. For example, throughcomputer 92, valve 77 b and 77 a can be kept partially closed causing arapid increase of the circuit pressure. When the accelerator of ICengine 43 is pressed, valve 77 b and/or 77 a can be set open and asurplus of torque is temporarily available to the IC engine 43. If theIC engine 43 is a large diesel engine, the pressure inside circuit 76can be adjusted such that boost power can be provided by AEF 11 to theengine every time the load is maximum (i.e. Truck or Bus facingsteady-to-accelerating conditions). If the IC engine 43 is a performanceengine, valve 77 b can be operated such that overpressures are availableat the engine intake manifolds allowing the injection of more fuelleading to increased overall engine power. If computer 92 is set tooperate in a continuous power mode, valves 77 b and 77 a can be activelyadjusted to provide power at all times. Probe 91 inside converter 88provides the necessary thermodynamic parameters to computer 92 which isalso able to shut-down the MWHE in case of overpressure, or any anomalydeveloped in the MWHE circuit. When MWHE is shut-down due to anomalies,computer 92 sets valve 97 open and discharges steam back to thecondenser 86, or, if the fluid is water, into the environment. In thiscase, to avoid overheating of the converter formed by channels 73, FIGS.15, and 16, fins 134, FIG. 15A are set open by computer 92 (ormanually). When fluid in the MWHE flows through valve 97, or is lost dueto breakage of the circuit, an optical and/or audio alarm is activatedthrough an electrical connection 114, or via computer 92. In general,computer 92 is a control system able to monitor analog or digital inputsproportional to crankshaft 44 RpM via sensor 55, AEF 11 speed via sensor56, EW 6 speed via sensor 115 (as described in FIGS. 3A, and 3B). Theseelectronic signals (conditioned by a conventional Input/Outputinterface) are processed by computer 92 which regulates the positions ofthe various valves and actuators accordingly (i.e. servo motors 112, viaelectrical connections 113, as described in FIGS. 3A, and 3B). Computer92 can be formed by a microprocessor structure user programmable orcustomizable by the insertion of specially mapped memories (i.e. pulsedor continuos mode operation of the miniaturized waste heat engine)

In FIG. 17A the hydraulic circuit of the MWHE utilizes a pressurizedtank 125 as a way to accumulate excess steam rather than dissipating itthrough the AEF 11 utilized in FIG. 17. As described earlier, excesssteam is produced because the heat produced by the engine provides moreenergy than that required to only power an oxygenator. However, thisexcess energy can be accumulated and returned to the IC engine in theform of boost pressure. By having such a high pressure availability whenthe IC engine is accelerating from idling RpM to high RpM, it ispossible to obtain significantly increased IC engine performance sincemore fuel can be burned given the increased availability of oxygen. InFIG. 17A, steam drives only an oxygenator designed to provide large massflow rates of oxygen to the IC engine regardless of its number of RpM.If converter 88 generates too much steam, the mass flow rate of fluidpumped by pump 87 can be reduced. This could cause a significanttemperature increase inside the converter. The excess energy fromconverter 88 can be utilized to provide very large mass flow rates ofair at high pressures by accumulating the excess steam inside tank 125.This configuration is particularly advantageous when the IC engine isoperated in an urban cycle (continuous accelerations and decelerations).Excess steam is regulated by valve 77 a connected to tank 125 throughinsulated piping and joint 126. Again, the pressure inside tank 125 isadjusted and controlled by computer 92. If the pressure inside tank 125increases beyond a pre-set threshold, valve 132 is set open by computer92 and steam condenses inside radiator 86 via piping 10. If an implodersystem is dimensioned to condense the same mass of superheated vaporentering the expander (i.e. 1 c and “I”, in FIG. 8), then radiator 86can be eliminated. If the IC engine idles for long periods the overallheat converted by converter 88 might not be sufficient to provide largeamounts of oxygen when requested by a sudden acceleration. In fact,Expander 1 might be in a situation where the mass flow rate of steam isinsufficient to provide enough propulsion for its CW 2 a. In this case,computer 92 opens valve 131, discharging steam pressure previouslyaccumulated directly through expander 1. The increased pressure insidehydraulic path 130 does not affect valve 77 b since a check valve 127prevents back overpressures inside hydraulic circuit 76. Valves 131 and132 are controlled by actuators 128 and 129, which are driven bycomputer 92. Tank 125 is thermally insulated through insulatingmaterials or through a jacket 133 in which a vacuum can be establishedthrough valve 124.

Converters with a poor heat transfer efficiency can be made by simplywinding a coil in thermal contact with the IC engine exhaust manifold,and/or muffler. To obtain an optimized transfer of energy from theexhaust gases to the MWHE, a compact and simple converter capable ofsustaining severe pressure fluctuations is represented in FIG. 18.Exhaust gases enter tube 98 flanged and sealed by seal 99 and allowingthe connection of multiple converters in series or parallel so as toform a bank of converters. The number of converters utilized depends onthe mass flow rate requirements and the amount of waste heat to berecuperated. Hydraulically sealed connections between various converterscan also be achieved through universal joints 107 shaped in any geometryto accommodate the IC engine compartment available space (i.e. elbowswith variable angles of inclination). The length and diameter of tube 98combined with the number of internal fins 100 and the distance betweenthe outer surface of tube 98 and the inner surface of tube 110 adetermines the amount of heat transfer capability of the converter. Thisheat transfer rate will also be proportional to a certain mass flow rateof the MWHE's working fluid. Fins 100 form a hydraulic path forcing thefluid to have a relatively long residence time inside the converter.Furthermore, this path forces the fluid to have intimate contact withthe inner surfaces of the converter, favoring an extremely rapid heattransfer. Water can be injected inside the converter through one of theinlet/outlet 101, 101 a or 102. The converter is symmetric and inletsand outlets can be exchanged. Generally, to improve the converterefficiency, the MWHE fluid inlet port should be chosen at the end of theexhaust gas hydraulic circuit (as far as possible from the combustionchambers). Arrow 105 represents liquid water, relatively cold, injectedfrom inlet 101 inside a converter (here represented open). As soon aswater is injected it expands, changing its specific volume by a factorof several thousands. This thermodynamic expansion provokes extremelyrapid steam/water accelerations inside the chamber formed by the outersurface of tube 98 and the inner surface of tube 110 a concentric withtube 98. Heat is added to the water, which becomes steam 106. Whilesteam travels inside the path formed by fins 100, its pressure andtemperature rapidly increase, making it superheated before it exitsoutlet 102. The number of fins 100 is variable and the inlet/outletports can be welded or threaded on the end cups sealing the jacketformed by tube 98 and 110 a. Inlet ports 101 a provide a sealedpenetration for temperature or pressure sensors. If these ports are notutilized they can be simply plugged. To minimize heat losses from theconverter to the surrounding environment, the converter can be thermallyinsulated by wrapping it with insulating material 104. To furtherimprove thermal insulation, a vacuum chamber 110 is formed by insertinganother concentric cylinder surrounding tube 110 a (sealed with the endcups). Air can be evacuated during manufacturing or through valve 109.If the heat transfer between exhaust gases and the fluid of the MWHE isoptimum, the temperature of the exhaust gases might drop so severelythat water produced during the combustion of fuel would start condensingtoward the end of the last converter 98 of a bank of converters. Byutilizing valve 108 inserted in one of the coupling joints 107positioned in the lower point of the converter bank (or even if it is asingle converter), condensed water in the exhaust gases can dischargewithout accumulating inside tube 98, minimizing corrosion. If the ICengine is equipped with a catalytic converter, the converters of theMWHE have to be inserted after the catalytic converter, or computer 92has to be programmed to produce steam in quantities that do not lowerthe exhaust gases temperature to levels that would damage or impair thecorrect functioning of the catalytic converter.

What is claimed is:
 1. A converter for converting heat energy fromexhaust combustion gases generated by a combustion engine, comprising: aheating chamber configured to be in thermal contact with and surroundinga discharge conduit of the combustion engine through which the exhaustcombustion gases are discharged, the heating chamber including two endportions and defining a hydraulic channel through which a fluid passes;an inlet port disposed in a first end portion of the heating chamber forreceiving the fluid into the heating chamber; an outlet port disposed ina second end portion of the heating chamber for discharging the fluidfrom the heating chamber; and an insulation chamber substantiallysurrounding the heating chamber, the insulation chamber comprising anaccess valve configured to fill, empty, or vent the insulation chamber,wherein the hydraulic channel is configured so that heat energy from theexhaust combustion gases is transferred to the fluid while the fluidpasses through the hydraulic channel.
 2. The converter of claim 1,further comprising a surface extension in the heating chamber configuredto increase a fluid residence time of the fluid within the hydraulicchannel.
 3. The converter of claim 2, wherein the surface extensioncomprises a plurality of fins extending from a surface of the heatingchamber that is in thermal contact with the discharge conduit.
 4. Theconverter of claim 2, wherein the surface extension comprises aplurality of structural fins extending along at least a portion of theheating chamber, the structural fins defining the hydraulic channel. 5.The converter of claim 2, wherein the surface extension is configured toextend across an internal surface and an external surface of the heatingchamber, the surface extension configured to withstand pressurefluctuation within the heating chamber, the external surface of theheating chamber also configured to serve as an internal surface of theinsulation chamber.
 6. The converter of claim 1, wherein the heatingchamber is configured such that the fluid enters into the heatingchamber in a liquid state and exits the heating chamber in a vaporstate.
 7. The converter of claim 1, wherein the access valve comprises amovable fin.
 8. The converter of claim 1, wherein the insulation chamberis configured to maintain a vacuum.
 9. The converter of claim 1, whereinthe heating chamber comprises a cylindrical body substantially enclosinga portion of the discharge conduit.
 10. A method of converting heatenergy from a discharge conduit of a combustion engine through whichexhaust combustion gases flow comprising: providing a heating chamber inthermal contact with and surrounding the discharge conduit, the heatingchamber including two end portions; providing an insulation chambersubstantially surrounding the heating chamber, the insulation chambercomprising an access valve configured to at least one of fill, empty, orvent the insulation chamber; injecting a fluid into the heating chamberthrough an inlet port at a first end portion of the heating chamber,wherein the heat energy from the exhaust combustion gases is transferredto the fluid in the heating chamber; and discharging the fluid from theheating chamber through an outlet port at a second end portion of theheating chamber.
 11. The method of claim 10, further comprisingincreasing a fluid residence time of the fluid within the heatingchamber by directing the fluid to flow along flow channels defined by asurface extension mounted to a surface of the heating chamber.
 12. Themethod of claim 10, further comprising: injecting the fluid into theheating chamber in a liquid state; and heating the fluid within theheating chamber so that the fluid exits the heating chamber in a vaporstate.
 13. The method of claim 10, further comprising substantiallymaintaining a vacuum in the insulation chamber.
 14. The method of claim10, further comprising draining condensate of the exhaust combustiongases from the discharge conduit.
 15. The method of claim 10, whereinthe heating chamber comprises a cylindrical body substantially enclosinga portion of the discharge conduit.
 16. A modular converter unitassociated with an exhaust conduit of a heat source to extract heat fromthe exhaust conduit, comprising: a discharge conduit having a first endand a second end, the first end being configured to connect to theexhaust conduit; a joint having a first end and a second end, the firstend of the joint being configured to connect to the second end of thedischarge conduit, the second end of the joint configured to connect toa discharge conduit of another modular converter unit; a heating chamberconfigured to be in thermal contact with and surrounding the dischargeconduit, the heat chamber including two end portions and defining ahydraulic channel through which a fluid passes; an insulation chambersubstantially surrounding the heating chamber, the insulation chambercomprising an access valve configured to fill, empty, or vent theinsulation chamber; an inlet port disposed in a first end portion of theheating chamber for receiving the fluid into the heating chamber; and anoutlet port disposed in a second end portion of the heating chamber fordischarging the fluid from the heating chamber, wherein the hydraulicchannel is configured so that heat energy from the exhaust combustiongases flowing through the discharge conduit is transferred to the fluidwhile the fluid passes through the hydraulic channel of the heatingchamber.
 17. The modular converter unit of claim 16, wherein the firstand second ends of the joint are interchangeable with respect to oneanother.
 18. The modular converter unit of claim 16, wherein the firstand second ends of the discharge conduit are interchangeable withrespect to one another.
 19. The modular converter unit of claim 16,wherein the heating chamber comprises a surface extension configured toincrease a fluid residence time of the fluid within the hydraulicchannel.
 20. The modular converter unit of claim 19, wherein the surfaceextension comprises a plurality of fins extending from a surface of theheating chamber that is in thermal contact with the discharge conduit.21. The modular converter unit of claim 19, wherein the surfaceextension comprises a plurality of structural fins extending along atleast a portion of the heating chamber, the structural fins defining thehydraulic channel.
 22. The modular converter unit of claim 19, whereinthe surface extension is configured to extend across an internal surfaceand an external surface of the heating chamber, the surface extension isalso configured to withstand pressure fluctuation within the heatingchamber, the external surface of the heating chamber is also configuredto serve as an internal surface of the insulation chamber.
 23. Themodular converter unit of claim 16, wherein the heating chamber isconfigured such that the fluid enters into the heating chamber in aliquid state and exits the heating chamber in a vapor state.
 24. Themodular converter unit of claim 16, wherein the insulation chamber isconfigured to substantially maintain a vacuum.
 25. The modular converterunit of claim 16, further comprising a second joint having a first endconnectable to the exhaust conduit of the combustion engine and a secondend connected to the first end of the discharge conduit.
 26. The modularconverter unit of claim 16, wherein the joint comprises a dischargevalve for draining condensate of the exhaust combustion gases.
 27. Aconverter system having a plurality of substantially identical modularconverter units for converting heat energy from the exhaust combustiongases, the system comprising: a first modular unit comprising: a firstdischarge conduit having a first end and a second end; and a firstheating chamber being in thermal contact with and surrounding the firstdischarge conduit, the first heating chamber including two end portionsand defining a first hydraulic channel through which a first fluidpasses; a first inlet port disposed in a first end portion of the firstheating chamber for receiving the first fluid into the first heatingchamber; a first outlet port disposed in a second end portion of thefirst heating chamber for discharging the first fluid from the firstheating chamber; and a first insulation chamber substantiallysurrounding the first heating chamber, the first insulation chambercomprising a first access valve configured to fill, empty, or vent thefirst insulation chamber, wherein the heat energy from the exhaustcombustion gases flowing through the first discharge conduit istransferred to the first fluid while the first fluid passes through thefirst hydraulic channel of the first heating chamber; a second modularunit, comprising: a second discharge conduit having a first end and asecond end; and a second heating chamber being in thermal contact withand surrounding the second discharge conduit, the second heating chamberincluding two end portions and defining a second hydraulic channelthrough which a second fluid passes; a second inlet port disposed in afirst end portion of the second heating chamber for receiving the secondfluid into the second heating chamber; a second outlet port disposed ina second end portion of the second heating chamber for discharging thesecond fluid from the second heating chamber; and a second insulationchamber substantially surrounding the second heating chamber, the secondinsulation chamber comprising a second access valve configured to fill,empty, or vent the second insulation chamber, wherein the secondhydraulic channel is configured so that heat energy from the exhaustcombustion gases flowing through the second discharge conduit istransferred to the second fluid while the second fluid passes throughthe second hydraulic channel of the second heating chamber; and a jointhaving a first end configured to connect to the second end of the firstdischarge conduit and a second end configured to connect to the firstend of the second discharge conduit.
 28. The converter system of claim27, wherein the first heating chamber comprises a first surfaceextension configured to increase a fluid residence time of the firstfluid within the first hydraulic channel, the first surface extensionextending across an internal surface and an external surface of thefirst heating chamber to withstand pressure fluctuation within the firstheating chamber, the first external surface of the first heating chamberalso serving as an internal surface of the first insulation chamber. 29.The converter system of claim 27, wherein the second heating chambercomprises a second surface extension configured to increase a fluidresidence time of the second fluid within the second hydraulic channel,the second surface extension extending across an internal surface and anexternal surface of the second heating chamber to withstand pressurefluctuation within the second heating chamber, the second externalsurface of the second heating chamber also serving as an internalsurface of the second insulation chamber.